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Test and debug regular expressions with live match highlighting and group capture
hello@example.comsupport@site.orgadmin@appygrid.comDiscover the powerful capabilities of our regex tester.
Matches are highlighted in real-time with color-coded spans as you type your pattern.
One-click toggles for g (global), i (case insensitive), m (multiline), and s (dotall) flags.
See every match with its position, length, and captured group values listed below.
Named capture groups (?<name>...) are extracted and displayed per match.
One-click examples for common patterns: email, URL, hex color, IPv4, and date.
Copy the full regex including delimiters and flags (e.g. /pattern/gi) with one click.
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Browse All ToolsThe Regex Tester is a free, browser-based utility designed for developer productivity. Test and debug regular expressions with live match highlighting and group capture Unlike desktop software that requires installation, this tool runs entirely in your browser — meaning no downloads, no accounts, and no data ever sent to a server. You get instant results right in your tab.
Whether you are a developer, student, writer, or designer, the Regex Tester saves time by automating repetitive tasks that would otherwise require expensive software or technical knowledge. It is completely free with no usage limits — use it as many times as you need.
There are many tools available online for developer productivity, but the Regex Tester on AppyGrid stands out for several reasons:
Getting started with the Regex Tester takes less than a minute. Here is a detailed walkthrough:
Enter Pattern
Type your regular expression in the pattern input field between the / delimiters.
Set Flags
Toggle g, i, m, s flags as needed using the buttons on the right of the pattern input.
Enter Test String
Type or paste the text you want to test against in the multi-line test area.
Review Matches
Matches highlight immediately. Check the Match Details panel for positions and group captures.
The entire process typically takes under 30 seconds. The Regex Tester is designed for speed — no waiting for server processing, no upload progress bars, and no page reloads.
The Regex Tester is used by a wide range of professionals and enthusiasts across different fields. Here are some common use cases:
No matter your background or use case, the Regex Tester delivers fast, accurate results without the overhead of heavyweight software or complex setup.
Here are detailed answers to the most common questions about the Regex Tester:
This tester uses JavaScript's built-in RegExp engine, which follows the ECMAScript standard. It supports most common regex features including lookaheads, lookbehinds, named capture groups, and Unicode (u flag).
g (global) finds all matches, not just the first. i makes matching case-insensitive. m makes ^ and $ match start/end of each line instead of the whole string. s (dotAll) makes . match newline characters.
Wrap part of your pattern in parentheses to create a capture group: (\w+). Use (?<name>\w+) for named groups. The Match Details panel shows all captured group values for each match.
Common errors include unescaped special characters (use \ before . * + ? { } [ ] ( ) ^ $ | \), unclosed groups or character classes, or invalid flag combinations.
Yes — everything runs in your browser using JavaScript's RegExp engine. No data is sent to any server.
AppyGrid is a free online tools platform built for developers, writers, designers, and everyday users. Every tool on AppyGrid — including the Regex Tester — is free, requires no account, and processes data entirely in your browser. We believe that useful utilities should be accessible to everyone, everywhere, without paywalls or data collection.
The Regex Tester is one of 38+ free tools available on AppyGrid, covering developer productivity, text processing, image editing, SEO, calculators, and more. Related tags for this tool include: regex, regexp, pattern, developer, test.
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